Support questions should be asked on Asterisk Support - this is a discussion forum.
zonedata.c is part of DAHDI, not Asterisk, so won’t be used at all for VoIP. Judging from the name of the table, I would suspect it is used as fallback values when the higher level application (Asterisk) doesn’t provide any information.
I can’t find “wanna” in my English dictionary, but CONGESTION tone is played when a call fails due to lack of network resources, including busy trunks, but, ideally, not including busy subscribers. STUTTER tone is played when a caller picks up their phone and there is a message waiting (generally voicemail). It replaces DIALTONE.
Note that most VoIP phones generate these tones internally, so are not affected by the files mentioned.